Long-Period P Waveforms and the Source Mechanism of Intermediate Earthquakes
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In this paper, the authors analyzed long-period P waveforms to interpret the source mechanism of four intermediate earthquakes with magnitudes of 6.0-6.5 and focal depths between 100 and 200km.Abstract:
Long-period P waveforms have been analyzed to interpret the source mechanism of four intermediate earthquakes with magnitudes of 6.0-6.5 and focal depths between 100 and 200km. The synthetic seismograms appropriate to each recording station have been constructed, to compare with observed records, on the basis of moving dislocation models with various parameters, including the fault length and width, the amount of dislocation, its time dependence and the fracture velocity, taking into account the combined effects of wave propagation in the earth and of a recording instrument. General features of the observed waveforms do not differ greatly from those for a double-couple point source, but the comparison with synthesized waveforms at a number of stations indicated seismic moment of order of 5-9×1026 dyne·cm, and also probable ranges for some other source parameters on tne assumed source. The bounds of the stress-strain drop, the released strain energy, and of efficiency of seismic wave radiation at the source were also discussed.read more
Citations
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Journal ArticleDOI
Distribution of stresses in the descending lithosphere from a global survey of focal‐mechanism solutions of mantle earthquakes
Bryan L. Isacks,Peter Molnar +1 more
TL;DR: A region-byregion analysis of 204 reliable focal-mechanism solutions for deep and intermediate-depth earthquakes strongly supports the idea that portions of the lithosphere that descend into the mantle are slablike stress guides that align the earthquake-generating stresses parallel to the inclined seismic zones as mentioned in this paper.
Journal ArticleDOI
Scaling relations for earthquake source parameters and magnitudes
TL;DR: In this article, the authors derived scaling laws for kinematic fault parameters such as length, width and rise time in terms of fault length and width, respectively, from a data set of 41 moderate and large earthquakes.
Journal ArticleDOI
The February 9, 1971 San Fernando earthquake: A study of source finiteness in teleseismic body waves
TL;DR: In this paper, a model of a propagating finite dislocation line source embedded in layered elastic media is proposed to determine detailed features of the source as a prelude to studying the near and local field strong-motion observations.
Journal ArticleDOI
Source parameters of intermediate and deep focus earthquakes in the Tonga arc
Max Wyss,Peter Molnar +1 more
TL;DR: In this article, the source dimensions, stress-drops and apparent average stresses of 19 Tonga-Kermadec earthquakes with depth greater than 79 km were estimated from the amplitude spectra of body waves.
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Temporal variation of the activity of intermediate and deep focus earthquakes
Katsuyuki Abe,Hiroo Kanamori +1 more
TL;DR: In this paper, the authors used a body-wave magnitude m_B determined from the maximum amplitude of body waves recorded by broad-band or long-period instruments to investigate the temporal variation of the activity of intermediate and deep focus earthquakes.
References
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Book ChapterDOI
Total energy and energy spectral density of elastic wave radiation from propagating faults
TL;DR: In this paper, it was shown that a shear fault is rigorously equivalent to a distribution of double-couple point sources over the fault plane, while a tensile fault is composed of force dipoles normal to the fault surface with a superimposed purely compressional component.
Journal ArticleDOI
Seismic moment, seismicity, and rate of slip along major fault zones
TL;DR: In this article, a straightforward method for computing rates of slip from earthquakes in major fault zones is presented, where the slip rate is calculated from the sum of moments for the earthquakes, provided that long time samples are considered and that adjustments are made in the vertical extent of the zone of earthquake generation.
Journal ArticleDOI
Body force equivalents for seismic dislocations
R. Burridge,Leon Knopoff +1 more
TL;DR: In this paper, an explicit expression for the body force to be applied in the absence of a dislocation, which produces radiation identical to that of the dislocation was derived for dislocations in an anisotropic inhomogeneous medium.
Journal ArticleDOI
Body Force Equivalents for Seismic Dislocations
R. Burridge,Leon Knopoff +1 more
TL;DR: In this article, an explicit expression for the body force to be applied in the absence of a dislocation, which produces radiation identical to that of the dislocation was derived for dislocations in an anisotropic inhomogeneous medium.
Journal ArticleDOI
Seismic moment, stress, and source dimensions for earthquakes in the California-Nevada region
Max Wyss,James N. Brune +1 more
TL;DR: In this paper, the authors studied the source mechanism of earthquakes in the California-Nevada region using surface wave analyses, surface displacement observations in the source region, magnitude determinations, and accurate epicenter locations.